A method and apparatus for performing a random access (RACH) procedure is disclosed. In one embodiment, a method performed by a wireless communication node, includes: performing a plurality of random access (RACH) procedures with a wireless communication device on a first frequency resource set and a second frequency resource set, wherein the plurality of RACH procedures each comprises: receiving a first message on a first frequency resource from the wireless communication device, wherein the first frequency resource is selected from the first frequency resource set; transmitting a second message on a second frequency resource to the wireless communication device within a pre-determined time window, wherein the second frequency resource is selected from the second frequency resource set; receiving a third message on the first frequency resource from the wireless communication device; and transmitting a fourth message on the second frequency resource to the wireless communication device.

A method and apparatus are disclosed herein for controlling transmit power in a station (STA) of a wireless local area network (WLAN). A STA may transmit, to another STA, transmit power step size information that indicates a maximum transmission power for an operational bandwidth that the STA supports. The STA may receive, from another STA, a signal in one of the plurality of operational bandwidths that the STA supports. The received signal may include a transmission power based on the transmitted adjustment step size setting.

According to one embodiment, a wireless communication device, includes a receiver configured to receive a first field, receive at least one of a plurality of second fields having been multiplexed and transmitted, and decode the one of the second fields to obtain a frame in a case where first information identifying the wireless communication device is not set in the first field, and a controller configured to suppress access to a wireless medium during a period indicated by a value set in the frame.

According to one embodiment, a wireless communication device includes a transmitter configured to transmit a first field containing information to identify a plurality of wireless communication terminals, and configured to multiplex and transmit a plurality of second fields in each of which a first frame containing an address of any of the wireless communication terminals is set; and a controller configured to determine, for the first frames, values pertaining to lengths of durations to suppress access to a wireless medium to the wireless communication terminal having an address different from the address contained in each of the first frames. The transmitter is configured to set the values in the first frames, the second fields, or the first field. The controller is configured to determine the values so that the durations have an end at an identical time.

A method for transmitting a physical layer protocol data unit (PPDU) and a device using the same are provided. The device receives a trigger frame for requesting a transmission of a high efficiency (HE) trigger-based (TB) PPDU and transmits the HE TB PPDU. A duration of the HE TB PPDU is calculated based on a duration of the trigger frame.

A wireless device receives configuration parameters indicating: a plurality of a channel occupancy time (COT) parameters of a COT of a cell; and a position parameter for the COT of the cell. A downlink control information (DCI) comprising a plurality of fields is received. The position parameter indicates a position of a field, of the plurality of fields. The field indicates a COT parameter, of the plurality of COT parameters. A transport block is transmitted via uplink resources of the COT with the COT parameter.

An example according to the present specification relates to a technique for configuring a preamble in a wireless LAN (WLAN) system. A transmitting STA may generate and transmit an EHT PPDU. The EHT PPDU may comprise an L-SIG field, an RL-SIG field, a first control field, and a second control field. A result of “modulo 3 operation” for a length field value of the L-SIG field may be set to “0.” The RL-SIG field may be configured to be the same as the L-SIG field. The first control field may comprise 3-bit information on the version of a PPDU, 6-bit information on a BSS color, and 7-bit information on TXOP.

A first base station may receive, from a second base station, cell configuration parameters of one or more cells of the second base station. The cell configuration parameters may indicating at least one first information element (IE) indicating a first identifier of a first cell of the one or more cells, at least one second IE indicating that the first cell is an unlicensed cell, and at least one third IE indicating radio frequency channel number of the unlicensed cell. The first base station may send, to the second base station, a handover request message for a wireless device after receiving the cell configuration parameters.

A user equipment (UE) communicates on a shared channel using sidelink transmissions. The UE determines a channel access priority for the sidelink transmission based on a channel access priority for the UE, a channel access priority associated with a packet priority of the sidelink transmission, a congestion level for the channel, or a remaining time in a packet delay budget of the sidelink transmission. The UE performs a channel access procedure based on the channel access priority for the sidelink transmission to assess that the channel is clear prior to transmitting the sidelink transmission, and transmits the sidelink transmission on the channel.

A frame transmission method, includes: sending, by a first communication end to a second communication end, a first RTS on an unlicensed channel, wherein the first RTS carries a licensed frequency band source indication; receiving, according to the licensed frequency band source indication, an assist-clear to send (A-CTS) that is sent by the second communication end in a retreat state on the licensed channel; and sending, according to the A-CTS, a first clear-request to send (C-RTS) on the unlicensed channel, wherein the first C-RTS is configured for instructing a third communication end to exit the retreat state entered based on the first RTS.